Note: All Scripture quotations found in this article are from the text of the Authorized King James Version of the Bible.
Teaching that one can lose their salvation can discourage people from getting saved and can also keep them from trusting the Lord Jesus Christ alone. The people that teach that salvation can be lost, teach that you have to do works along with faith to be saved and to keep yourself saved. This thinking can lead people to hell.
They get this false doctrine from not rightly dividing the word of God(2 Timothy 2:15). When we look at the Pauline Epistles that are doctrine for the Church Age Saint we see that we have Eternal Security and salvation is by faith alone.
Romans 10:4 "For Christ is the end of the law for righteousness to every one that believeth."
Romans 11:6 "And if by grace, then is it no more of works: otherwise grace is no more grace. But if it be of works, then is it no more grace: otherwise work is no more work."
We are told in God's word that if we believe on Jesus Christ that we can KNOW that we have eternal life. It is a guaranteed thing.
1 John 5:13 "These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life, and that ye may believe on the name of the Son of God."
Paul was the Apostle to the Gentiles(us) and preached the gospel of the grace of God. This gospel consists of the death, burial and resurrection of Jesus Christ.
1 Corinthians 15:3 "For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures; 4 And that he was buried, and that he rose again the third day according to the scriptures:"
We know that we have Eternal Security because of the sealing of the Holy Spirit.
Ephesians 1:13 "In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise,"
Ephesians 4:30 "And grieve not the holy Spirit of God, whereby ye are sealed unto the day of redemption."
We are justified and redeemed by Christ alone. ALL of our sins are forgiven by the Blood alone and we have his righteousness, if we are saved.
Romans 3:24 "Being justified freely by his grace through the redemption that is in Christ Jesus: 25 Whom God hath set forth to be a propitiation through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God;"
1 John 1:7 "But if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin."
We are kept by the power of God and not ourselves. That means salvation cannot be received or kept by anything WE do.
1 Peter 1:5 "Who are kept by the power of God through faith unto salvation ready to be revealed in the last time."
Philippians 1:6 "Being confident of this very thing, that he which hath begun a good work in you will perform it until the day of Jesus Christ:"
I Corinthians 1:8 "Who shall also confirm you unto the end, that ye may be blameless in the day of our Lord Jesus Christ. 9 God is faithful, by whom ye were called unto the fellowship of his Son Jesus Christ our Lord."
The Blood of Jesus Christ was an eternal offering for our sins.
Hebrews 10:10 "By the which will we are sanctified through the offering of the body of Jesus Christ once for all."
NOTHING can separate us from the love of Christ.
Romans 8:35 "Who shall separate us from the love of Christ? shall tribulation, or distress, or persecution, or famine, or nakedness, or peril, or sword?
36 As it is written, For thy sake we are killed all the day long; we are accounted as sheep for the slaughter.
37 Nay, in all these things we are more than conquerors through him that loved us.
38 For I am persuaded, that neither death, nor life, nor angels, nor principalities, nor powers, nor things present, nor things to come,
39 Nor height, nor depth, nor any other creature, shall be able to separate us from the love of God, which is in Christ Jesus our Lord."
We are promised eternal life and told that no one can pluck us out of the hand of God. Remember God CANNOT lie.
John 10:28 "And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand."
John 3:16 "For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life."
Titus 1:2 "In hope of eternal life, which God, that cannot lie, promised before the world began;"
We are said to be the sons of God once we believe and we're also said to be IN Christ. That means we are part of God's family and we're in the Body of Christ.
John 1:12 "But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name:"
Romans 12:5 "So we, being many, are one body in Christ, and every one members one of another."
1 Corinthians 1:30 "But of him are ye in Christ Jesus, who of God is made unto us wisdom, and righteousness, and sanctification, and redemption:"
2 Corinthians 5:17 "Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new."
Galatians 3:26 "For ye are all the children of God by faith in Christ Jesus."
There are many other verses that say we are IN Christ, but with that in mind, take a look a the below scripture.
Matthew 7:23 "And then will I profess unto them, I never knew you: depart from me, ye that work iniquity."
If when we are saved, we are put IN the Body of Christ and made the children of God. With that being said, Jesus Christ cannot look at us and say that He never knew us because He did, we are IN His body.
Eternal Security is a true Biblical doctrine and the ONLY way not to believe it is to not believe what God has told us in the scriptures. For me, I take God at His word.